Extended coverage-Global System for Mobile Communication (“EC-GSM”) is technology utilized to facilitate realization of Cellular Internet of Things (“CIoT”) in order to support networking of Internet of Things (“IoT”) devices that may be associated with low complexity and throughput.
In EC-GSM, the signal levels may be very low, which may result in an input signal to noise ratio (“SNR”) being too low for a legacy GSM equalizer to work properly. In-phase/quadrature (“IQ”) accumulation has been proposed to increase the SNR before the equalizer. However, IQ accumulation is very sensitive to a frequency offset. Sometimes, five or ten Hz frequency offset may lead to an obvious performance degradation. Thus, a powerful frequency offset estimation (“FOE”) algorithm may be desired to provide accurate frequency offset estimation.